I have a question regarding the upgrades of most of the recon groups of the luftwaffe. They now change to Fi 156 if left on auto (not only the groups attached to the Army HQs, but also some of the groups initially equipped with BF 110 C-5 for example). Are the groups actually upgrading as intended? Changing from Hs 126 to FI 156, ok, But from FW 189 or BF 110 C-5 to Fi 156? that does not make sense

Side-effects of the more aggressive a/c swap function. Both Bf 110 and Fw 189 are usually understrength units or low on replacements so they fulfil the prerequisites for swap. Sadly we only have the recon a/c class and not a short- and long-range recon, this would prevent these long- to short-range swaps.

I plan to work through the aircraft file this month, setting an upgrade path from Hs 126 to Fi 156 may be an option.

But would that mean automatic swaps? I'm asking because basically most of the time I just strip departing squadrons of Hs126s and a few select others to create an artificial pool of replacements. In my opinion the HS126 is actually a better plane than the Fi 156. Regarding the FW189, it seems that despite to low production numbers, one can keep their squadrons up to strength simply by either stripping departing squads or just waiting for the winter seasons to replenish them. Regarding the 110s (and the Dorniers as well), only selected swaps of airframes can actually keep up certain numbers in hand.

An upgrade path set would see them changed to Fi 156, not swapped. Both actions won't happen with aircraft update set to manual (either via CR or in-unit).

The Hs 126 is better than the Fi 156 but they are also of a different class. Fi 156 was for rather short flights vs the somewhat longer range of the Hs 126 (which was being replaced by the Fw 189).

Agreed. And given that the FW189 has such low production numbers, the Hs 126 is still a vital aircraft as medium ranged recon till 1943. After that, there are enough Fw189s and even the Recon versions of the Me109 and JU88 to steadily convert recon squads to Long range recon (partly also due to steady reduction in the numbers of recon squadrons)

BTW I use the Fi 156 as well to place them into withdrawing units just to get rid of them.

Same here unless the unit is so depleted (say with 4 planes remaining) that it isn't worth it. The Fi 156 is the most useless German plane with the possible exception of the Gotha night bomber which is basically a useless flying crate.